Drilling machine



Patented June 15,1926,

UNITED sraras Parent" oFFlCE.

GEORGE H. GILMAN, OF BOSTON, MASSACHUSETTS..

niiiLLiiie riaoiiiivn.

The invention ielates to drilling machines and more particularly but not exclusively to hammer rock drills. l

The invention will be best understood from the following description when rea-d in connection with the accompanying drawings7 of an example of the invention, while the scope of the invention will be more par-V t-icularly pointed out in the appended claiins. In the drawings: p Fig. 1 is a longitudinal section through a hammer rock drill; l

Fig. 2 is Va section on the line 2-2 of Fig. V1; -f

Fig. 3 is a section on the line 33 of Fig. 1; Fig. t is a sectionon the line td/i of Fig. 1;

Fig. 5 is a fragmentary section corresponding'to Fig. 1 showing the valve at the opposite end of its travel; and

Fig. 6 is a section on the line 6 6 of Fig` 3 with the valve omitted.

Referring particularly to 1 to 4,`

the embodiment of my invention which I have selected for purposes of illustration includes a casing comprising a cylinder` member 1, .a front head structure 2 and rear head structure 3. Mounted. for reciproca' tion in the cylinder' isa piston d provided with a hammer bar 4 while rotatably' mounted in the front head structure is va chuck 5 provided with a polygonal recess for receiving the polygonal end 6 of the drill'V steel 7. The drill steel is arranged in the present construction to be impacted by the hammer bar, the latter extending from thel cylinder into Vthe front headstructure and being surrounded by the rearwardly ex-v tending portion 8 of the chuck.

As shown in the rear head structure t is mounted a ratchet disk 10 provided with a bar 11 extending through the cylinder.

and into the recess 9 of the piston, the teeth of the ratchet disk cooperating with suit-v able spring pressed pawls 12 to permit ro tation of the bar in the direction indicated y by the arrow in Fig. 1 and to prevent rotation in the opposite direction. Cooperating with the hammer bar in a manner hereinafter to be described I have shown a ratchet ring 13 mounted in the front vhead structure and surrounding the hammer bar,

the ring being provided with la rearwardgrooves and cooperating followers. grooves of the connection between the bar Application led April 3U, 1920. Serial No. 377,763.

ly extending portion 14 rwhich provides an exterior bearing for the ring in the front cylinder head 15 as is clearly illustrated by Fig. 1. On the exterior surface ofthe ring 13 I provide ratchet teeth which cooperate .with the spring pressedV pawls 2O tol prevent rotation .of the'ring in the direction kopposite to that indicated by the arrows around the rifle bar .and the drill steel.l

f For connecting the piston to the bar 11 and for connecting the hammer bar to the chuck and the ring I have herein provided slots or The 11 andthe piston are preferably formed yon the exterior surface of the bar an-d the followers on the interior surface of the nut 16' carried bythe piston. The` grooves vof the connections between both the ring and chuck oblique to' the axis of the piston and hammer bar while the grooves connectingthe hammer bar to the ring are preferablyin the form of straight grooves 19 for forminga .feather connection. Respectively cooperf ating with the grooves 1'?7 18 `and 19 are the lugs 21, 23 and'22. For the reason hereinafter pointed out7 the gooves 18 are prefv erably of .one-half the pitch of the grooves on thebar 11 and'both sets of grooves are pitched in the same direction. `VThe bar 11 will hereinafter be referred tolas the rifle bar.

The operation of the mechanism .so far.

described is as follows: When motive fluid is admittedto drive the piston from the poe sition 'shown in Fig. 1 to the rear end of the cylinder, the piston, owing. to the action of the cam surfaces afforded by grooves 18 and their followers, tends to rotate in the direction oppositel to that indicated by the arrows in Fig. 1. This rotation is prevented by tlie pawls cooperating with the ring and consequently the piston moves backwards without rotation and this through the action of the grooves 18 and their fol` lowers rotates the chuck. and rifle barv in the direction indicated by the arrows. When motive fluid is admitted to drive the piston from the VVrear to the forward end of the cylinder, the piston tends to rotate the yrifle bar in the direction oppositeto that indicated by the arrows in Fig. 1. This rotation is prevented by the pawls cooperating with the teeth on the ratchet and consequently as the piston advances, it is rotated by the action of the followers 21 on the cam surfaces afforded by the grooves 17 in the direction of the arrows and therefore it rotetes the chuck throughthe action of the grooves 18 and cooperating followers 23, During the forward stroke the ring 13 rotates with the piston. It will be noted that a forward reciprocation of the piston .tends to rotate the chuck .relatively thereto by acion of the grooves 18 in the opposite direction to which the piston is then rotating and therefore, Vthe absolute rotationof the chuck is dependent upon the difference in pitch between these grooves and the 2grooves 17 on the rifle bar. Consequently if the pitch of the Agrooves 18 is one-half that of the grooves -17 the chuck is rotateddat vone-half the speed 4of .rotation of the piston or 1n other words, it is rotated yat the same speed or through the same angle Von the forward stroke of the piston as it is rotated on the rearward stroke of the piston.

For controlling the active fluid for reciprocating the piston I have shown va suitable valve 24 mounted in the casing 25 formed integrally with the cylinder portion and extending longitudinally of the cylinder at one side thereof. This casing I preferably construct t-o form a reduced diameter portion 26 and an enlarged diameter portion 27. In the enlarged vdiameter portion are provided the annular grooves 28 and 29 while in the reduceddiarneter portion areprovided the annular grooves 30 and 31. The grooves 28, 29, '30 yand 31 respectively communicate with lthe cylinder by means of Vpassages 32, 33, 34,35.

Mounted for reciprocation within the valve `casing is a vvalve 24 provided withthe heads 36 and 37 -of diameters corresponding to those of the enlarged and` reduced portions of the valve casing. Intermediate the heads 36 and 37 the valve is provided with the reduced portion k38. This valve is tubular inform, being provided with the internal conduit 39.

At Athe end of the enlarged head 3.6 of the valve is formed a poppet seat 40 cooperating with the corresponding valve seat 41 formed on the bushing 42, this bushing being provided with a passage 43 communicating with the motive fiuid supply 44. Y

lComin-imieating with the valve casing iintermediate the heads 36 and 37 are conduits 45 Aand 46 and formed in the interior wall of the cylinder is a longitudinally extending groove 47 with which the passage 34 communicates. Preferably, I forni one portion of the head 36 adjacent the poppet seat with a bevel 48 and provide the forward end of the bore of the valve with a similar bevel 49, These bevels, although they are not'absolutely necessary for the successful operation of my valve are provided to improve its efiiciency.

The operation of the valve is as follows: Assume the valve is in the position illustrated byFig. 1. Under these conditions, the motive fluid passes through the bore 39 of the valve and flows aroundrthe rear end thereof and enters the forward end of the cylinder through ,the groove 31 and passage 35. The pistonnow moves rearwardly, the motive fluid kin front of the piston exhausting through the vpassage 33 and annular groove 29 into the space about the reduced portion 38 of the valve. whence it discharges to the atmosphere through the passages 45 and v46.

After the piston moves rearwardly far enough to cover the port 33 the motive fluid in front of the piston is trapped and cornpressed lto a high enough pressure to overcome the pressure of the motive fluid on the forward end of the valve, this compressed Huid acting on the poppet face and it'sfbevel 48 to throw the valve forwardly.

When the valve .moves forwardly,V the pressure actingon the poppet face 40 holds the valve in'its forward position as illustrated by Fig. 5 and the motive fluid now flows across the seat vand enters the cylinder through the passage 32 and 'forces thepistfon forwardly, the motive fluid now exhausting through the ,groove 47,' passage 34, annular space around the reduced portion of the valve and passages 45 and 46 to the atmosphere. In its forward stroke, after the rear end of the .piston uncovers the groove 47 the motive fluid behind the piston discharges to the exhaust and reduces the pressure of the air on-the poppet seat of the valve, This reduction of pressure permits the live air acting on the forward end face of the valve and its bevel 49 to throw the valve rearward-- ly. It will be appreciated that the opening of the groove 47 to the high pressure air behind the piston builds upV a considerable pres- 7 sure in the exhaust chamber formed Vby the reduced portion 38 of the valve and this pressure acting on the `unbalanced area of the head 36 aids the live air actingl on the forward end of the valve to move it. vThe position of the parts are now as shown by'Iig. 1 and the operation is repeated.

lli)

The lgroove 47 is made of such dimensions as to permit a prolonged exhaust-on the forA` ward stroke .of the piston and the exhaust of air from behind the piston on this stroke at the proper time to throw the valve rear-- wardly. It will be noted that the groove 47 when uncovered by the piston connects the admission passage 32 with the exhaust pas- 36 of the valve in luidcommunication.

Although I have described one specific embodiment of my invention it is to be understood that my invention is not limited thereto and that extensive deviations may be made without departing from the spirit ofl my invention.

Claims:

l. In a hammer rock drill, a casing, a chuck rotatably mounted in said casing, a hammer piston in said casing having a hammer bar, a rifle bar having a helical groove and lug connectionwith said piston and atchet connection with said casing, a ring surrounding said hammer bar and having a ratchet connection with said casing; lug and groove connections between said hammer bar and ring and hammer bar and chuck, one of which grooves is helical andthe other parallel to the axis of said chuckl and the direction of rotation of said rifle bar and ring permitted by the respective ratchets and the pitch of said helical grooves being such as to enforce rotation of said chuck for each direction of reciprocation of said piston.

2. In a hammer drill, a hammer piston, a drill steel, means for rotating said piston on one of its strokes, means for preventing rotation of the piston on the next successive stroke, and a connection between said piston and drill steel so formed that on each 4of said strokes the steel is rotated in the same direction. i

3. In a hammer drill, a hammer piston, a drill steel, a chuck carrying said drill steel means for rotating said piston onone of its strokes, means for .preventing rotation of the piston on the next successive stroke, and a connection between said piston and chuck so formed that on each of said strokes the chuck is rotated in the same direction and at the same speed.

el. In a hammer drill, a piston, a chuck, means for holding the piston from rotating on one stroke, a connection between the piston and chuck for causing therectilinear motion of the piston to rotate the chuck when sor held, and means for rotating the piston on the opposite stroke whereby the piston through said connection rotates the chuckin the same direction. y

5. In a hammer drill, a piston, a chuck, means for holding the piston from rotating' on one stroke, a connection between the piston and chuck for causing the piston to rotate the chuck when so held, and means for rotating the piston on the opposite stroke at twice the speed that the chuck was rotated on the first mentioned stroke whereby the piston through said connection rotates the chuck in the same direction as before and at the same speed.

6. In a rock drill, a casing, a hammer piston therein having a hammer bar, a chuck, a helical lug and groove connection between said hammer bar and chuck, means for. causing theI piston to travel with a predetermined angular movement relativeto saidca'singon the rear stroke whereby said chuck is rotated, and means for'rot'ating said piston on the opposite strokewhereby said chuck Iis again rotated in the same direction.

7. In a rock drill, a casing, a hammer piston therein having a hammer bar, a chuck, a helical lug and groove connection between said hammer bar and chuck, means for causing the piston to travel with a predetermined angular movement relative to said casing on the rear stroke whereby said chuck is rotated, and means for rotating said piston on the opposite stroke whereby said chuck is again rotated in the same direction, and at the same speed.

8. In a rock drill, a casing, a hammer piston therein having a hammer bar, a chuck, a helical lug and groove connection between lsaid hammer bar and chuck, means for causing the piston to travel with a predetermined angular movement relative to said casing on the rear stroke whereby said chuck is rotated, and a rifle barv operative toI ro'- tate said piston on the opposite stroke wherein the same direction and at the samerspeed.

ion

10. In a hammer drill, a casing having therein a rotatable chuck and a hammer piston, a helical cam connection between said piston `and chuck, means including a pair of ratchet devices having a slip connection with saidpiston for causing said piston to rotate on one stroke. in the same direction as that in which said chuck rotates and be withheld from rotation on the other stroke, and said ratchet devices being rotatable in only one and the same direction, whereby said pistonwhen withheld from rotation rotates said chuck in one'direction and when rotated rotates said chuck inthe same direction.

11. In a hammer drill, a casing having therein a rotatable ychuck and a hammer piston, a helical cam connection between said piston and chuck, a pair of ratchet devices rotatable in only `one and the same direction, a slip connection between one of said ratchet devices and said piston comprising a helical lll @am `Connection of twice the pitch as the piston from rotating on the opposites-Hohe first named helical 4*cam connection 01' .lofoy causing said piston to rotate Sad Chuck 10 tating said piston on one stroke? whereby at thersame speed and in the same .dleoton said piston rotates sai-d chuck Vtn lthe same as on the first mentioned Stroke. v

direetonztssad pstonat-onefhalffthe Spee-d In testimony whereof, I have signed my of lrotationfof said piston, andfa slip eonneenaine to this specification. tion between the other ot said ratchet devcesend said piston for preventing said GEORGE H. GILMAN, 

